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By Paul L. Campbell

Investigations by the Federal Bureau of Mines of methods of upgrading tar obtained by low-temperature carbonization of lignite showed that ß,ß?-oxydipropionitrile, ß,ß?-iminodipropionitrile, and ß,ß'-thiodipropionitrile were effective solvents for extracting aromatics (aromatic hydrocarbons plus polar compounds) from coal-tar neutral distillate fractions. Batch extraction showed that these solvents extracted approximately the same percentage of aromatics from various neutral oil fractions boiling between approximately 170° and 350° C. In continuous countercurrent extractions using oxydipropionitrile and iminodipropionitrile, approximately 30 to 35 vol.-pct, and 65 to 70 vol.-pct, of the aromatics in 170° to 350° C. neutral distillate oil were extracted at room temperature when solvent-to-oil ratios were 2:1 and 12:1, respectively. As the concentration of aromatics in the neutral distillate oil fraction decreased, the capacities and, to some extent, the selectivities of these solvents for the remaining aromatics decreased. Aromatics were isolated from the extracts and the solvents recovered by washing the extract fractions with a low-boiling paraffinic hydrocarbon such as heptane, using hydrocarbon-to-extract ratios of at least 2:1. The heptane wash removed most of the aromatics but only part of the polar compounds (compounds containing oxygen, sulfur, and nitrogen) from the extracts. The recovered oxydipropionitrile and iminodipropionitrile, containing polar compounds, were effective in extracting aromatics from neutral distillate oils. The contaminated solvents showed essentially the same capacities and selectivities as the pure solvents.

Jan 1, 1961

By R. F. Randolph, R. S. Fowkes, J. J. McClelland, G. H. Schnakenberg

Between 1986 and 1992, there were268 deaths and 54,642 severe injuries to workers in underground U. S. mining operations. Clearly, this level of health and safety risk is not acceptable. While most underground coal mining jobs are dangerous, some are much more dangerous than others. Many jobs in an underground coal mine are clustered around the working face—the place where machinery digs coal from the surrounding rock. The hazards in this area are numerous: When the coal is removed, the ground around it becomes unstable and can cave in on the workers. The mining machines used there are large, heavy, powerful, and move in many different directions in a very confined space, presenting danger to workers. Also, the machines churn up coal dust that causes black lung and other ailments. Figure1 shows a modern radio remote controlled continuous mining machine and its operator. In a typical mine, the jobs with the greatest exposure to hazards involve operation of machinery that cuts tunnel-like passages into the coal (the continuous mining machine) and machines that insert supportive steel bolts into the rock above the work area (roof bolting machines). The workers who endure these hazards are at almost twice the risk of death or disabling injury than co-workers in other safer areas of the mine. Of the statistics quoted above, 106 of the 268 deaths and 21,552 of the 54,642 severe injuries occurred in jobs involving equipment at the working face. The operators of roof bolting and continuous mining machines account for only 21% of the work force but suffered 40% of the deaths and 39% of the lost-time injuries during1986-1992. These death and injury rates are almost twice the rate for workers in other underground mining jobs (see figure 2). The estimated total cost of the 106 fatalities and21,552 lost-time injuries was $327 million from 1986-1992. On average, each fatality cost over $1 million and each lost-time injury costs in excess of $9,000.

Jan 1, 1994

By Larry A. Haas

The Bureau of Mines is investigating the use of complex gas mixtures, such as would be produced by coal gasification, for reducing iron oxide pellets. A semiempirical model was developed to predict a priori the reduction rate of an iron oxide pellet in a laboratory tube furnace with simulated coal gases at a total pressure of 1 atm. The model uses partial pressures of H2, CO, CO2, CH4 (methane), water vapor, and a temperature-dependent term to predict the rate of reaction. The reduction rate (weight loss per unit of time) was determined with a thermo-gravimetric apparatus (TGA) in the temperature range of 800° to 1,100° C. The ranking of the reductants, in order of decreasing reducing potential, is H2, CO, and CH4 at temperatures between 800° and 1,000° C; however, CH4 became a better reductant than CO at 1,100° C. Water vapor did not decrease the reduction rate as much as did CO2, Carbon deposition was observed at temperatures below 1,000° C with gas mixtures with high CO and low H2 concentrations. With low-Btu gas at 900° C, over 90 pct of the iron oxide was reduced to iron in less than 3 h. This com-pares with a reduction time of 1.5 h with medium-Btu gas and 1 h with reformed natural gases.

Jan 1, 1985

By M. M. Fine

A process for simultaneously reducing and indurating iron are pellets was developed by Bureau of Mines laboratory research and confirmed on a continuous pilot plant basis. Moist iron are concentrate was balled, mixed with solid reductant, and heated at about 1,100° to 1,150° C. On a small scale, a variety of concentrates and fuels were utilized successfully. The pilot rotary kiln tests were limited to natural magnetite, synthetic magnetite, lignite, and anthracite. In both cases, partially reduced pellets with excellent physical properties were regularly produced with average analyses of at least 80 percent total iron and 60 percent or more metallic iron. These and other prereduced pellets were smelted in the Bureau's experimental blast furnace facility, Bruceton, Pa. With prereduced spheres comprising 85 percent of the burden, the coke rate was approximately half that with standard oxide pellets and production of hot metal was increased by 75 percent. Economic appraisal of the cost of making hot metal indicates that reduced pellets could be more profitable than any other iron raw material in both investment capital and daily cost of operation.

Jan 1, 1970

By Ernest Ph. Hérivel

The mine and treatment plant of the Teziutlan, unit of the Mexican Corporation, S. A., are located at Aire Libre, in the District of Teziutlan, near the northwest edge of the State of Pueblo, Republic of Mexico. The property is leased from the Teziutlan Copper Co. The town of Teziutlan is the terminus of a branch railroad starting from Oriental Junction or the Mexico-Jalapa-Veracruz narrow-gage system of the National Railways of Mexico. A branch line 18 km in length from Teziutlan to Aire Libre belongs to the Teziutlan Copper Co. and is leased and operated in conjunction with the mine.

Jan 1, 1933

By J. P. Schmid

Results of a comprehensive investigation of the impact of underground mine waste disposal on the health and safety of miners are presented. Information was gathered through an extensive search of American and foreign literature and personal communication with professionals in private industry and government. All conceivable health and safety hazards directly or indirectly related to underground mine waste disposal are analyzed, catagorized, and ranked on an industry-wide basis. Positive health and safety effects are analyzed and ranked in a similar way. Both potential and known hazards and positive impacts are included. Recommendations on abatement techniques for the various hazards are presented. Case histories of a fill-related accident in a metal mine and a health hazard associated wtih coal waste backfilling are included and causes and possible abatement procedures are discussed. The rule of management in the promotion of health and safety in backfilling operation is discussed.

Jan 1, 1982

By Michael R. Norland

Surface and subsurface stabilization of mining-related wastes through revegetation depends upon the physical, chemical, and biological condition of the waste following mining. Mining disturbances can significantly alter the soil physical, chemical, and biological characteristics of a site, reducing or eliminating mycorrhizal fungi from the soil. Mycorrhizae are economically and ecologically important because they can alleviate environmental stresses caused by lack of proper soil condition and because they are vital to stabilization of mining waste by increasing plant survival and biomass through increased nutrient and water uptake. This report discusses some of the ecological factors that may affect mycorrhizae-plant associations on mining-related wastes and provides general information on mycorrhizae inoculation technology.

Jan 1, 1993

By Earl Redman

The Juneau Gold Belt portion of the Juneau Mining District has historically had the greatest mining and exploration activity within the district. Between 1880 and 1983, the mines within the Juneau Gold Belt produced 6.7 MM oz gold, 3.1 MM oz silver, and 45 MM lbs lead, which had a total value of about $157,000,000 at the time of production. This report summarizes Bureau of Mines work completed in 1986, the second year of the Juneau Mining District study. Fifty mines, prospects, and occurrences were examined and 638 samples were collected for analysis during 1986. Metallurgical samples were collected from seven deposits and preliminary tests of cyanide amenability have been completed for five of these. The simultaneous discovery by private industry and the Bureau of gold-bearing quartz veins cutting diorite gneiss recently exposed by the retreat of the Herbert Glacier is the most notable result of work during 1986. This location yielded gold values up to 7 oz/st.

Jan 1, 2011

By Robert E. Barieau

A list of 163 references to original experimental PVT data on helium is presented for the period 1895 to 1968. The list is complete as of the start of the Helium Centennial Year, 1968, to the best of the author's knowledge. Citations were keypunched for easy updating and are listed alphabetically by author.

Jan 1, 1968

By C. F. McCarroll

The effectiveness of an industry's safety activities can be gaged best by the accident records of that industry. In an effort to gage conditions in the petroleum industry, and with the objective of helping to reduce the number of accidents in it, the Bureau of Mines from time to time has tabulated, analyzed, and published pertinent statistical information.3/. These reports have dealt with distribution, causes, and costs and related phases of accidents for various and collective divisions of the petroleum industry in several sections of the country. This type of study aids the personnel of the Bureau in planning the course of its activities in accident-prevention work and gives useful data to persons engaged or interested in the promotion of safety in the petroleum industry, which will aid them in their efforts to reduce the number and severity of accidents. A majority of petroleum operators and "service? contractors have acknowledged their responsibility to provide their employees with safe working conditions and to their stockholders for greater economic value of invested capital by establishing safety divisions within their respective organizations. Such divisions have a primary duty, namely, to see that properly designed and guarded machinery and working equipment are furnished the employees and that they are trained in the safest practical methods of performing their work. Some companies and individual operators, however, have shown little or

Jan 1, 1939

By Jack Wright

The analysis of water produced with crude petroleum has interested oil producers since inception of the industry. Records of the first analysis of mineralized water produced from an oil-productive formation are obscure, and references to the first use of brine analyses to assist in solving problems of petroleum production are not available in the technical literature. However, many early reports of the Federal Bureau of Mines5-8 and Federal Geological Survey,9-11/ as well as articles in engineer and geological journals12-14/ placed special emphasis on the importance, interpretation, and application of water analyses. One of the earliest applications of water analyses, and still a major one today, is for identification of intrusive waters in oil wells. This may be done by comparing the chemical constituents of a sample of water indigenous to the oil-productive formation with those of samples from upper, water-bearing formations within the same general area. Some earlier investigators recognized the need for Analyzing samples of all waters encountered in drilling operations. Ambrose15/ stated, in part, "In wells being drilled, the engineer should grasp every opportunity to get a true sample of water from each sand. . .," and, "The waters of each oil field are chemically different from those of another field." The validity of the latter observation and the importance of the former one have been borne out by comparing the results of analyses of many samples and noting the differences in relative concentrations of like constituents of waters from the a geological formation in different localities or oil pools.

Jan 1, 1957

By John D. Spencer

Surveys to establish the quantity and quality of coals available for metallurgical, industrial, and energy use, investigations to develop better mining methods, and studies aimed at improving the health and safety of those who mine the coal highlighted Bureau of Mines research and technologic work on coal in 1968. Also being developed are more efficient methods of coal preparation, transportation, storage, and utilization. Supplementing this effort are projects designed to assure minimum disturbance of land, water, and air resources. Research centers and laboratories of the Bureau of Mines are listed in appendix A. Publications released during 1968 are cited with the various projects and in appendix C. Organizations that cooperated in the work in various ways are cited in appendix B.

Jan 1, 1969

By Henry M. Harris

The roll forming of oxide powders was studied in a Bureau of Mines investigation to find the conditions and parameters required to make satisfactory ceramic strip. High-quality porous or dense alumina, zirconia, and porcelain shapes were made by sintering strip roll-formed at room temperature from powders containing minor amounts of binder and water. Strips with thicknesses of 0.04 to 0.08 inch and bulk densities from 40 to 90 percent of theoretical densities were made. The parameters most important to formability were particle size, condition of the powders, and roll gap. Other factors affecting quality were speed and surface condition of the rolls, amount and type of binder, water content, and sintering conditions. Ceramic strip was formed at rates up to 78 feet/minute, which is 13 to 23 times faster than reported by previous investigators, and forming was done in a simple and inexpensive roll unit. Reshaping the strip was possible by cutting, grinding, shearing, and stamping. The following innovations were developed that allow roll processing not normally possible with ceramic powders: (1) Fine-sized powders were made into strip by preparing these as partially sintered granules; (2) thick strip was formed by pressure feeding powders into the rolls; (3) flexible strip was made using a rubber-base bonding agent; (4) corrugated strip was formed on shaped rolls; and (5) porcelain strip was densified and reduced in thickness by rerolling while hot.

Jan 1, 1970

By J. B. Zadra, S. M. Shelton, R. B. Fisher, M. M. Fine

"INTRODUCTION An extensive test program is in progress by the Bureau of Mines to determine ways and means of recovering ferromanganese ore 5/ from the widespread domestic manganese and manganiferous iron deposits.Samples were received from the Stance property in southwestern Virginia, 12 miles northwest of Stoney Gap, in Bland County.The Stange mine is situated on the crest of Flat Top Mountain and is developed by open-cuts extending over several acres. The manganese deposit occurs in the Oriskany sandstone largely as a replacement of the sandstone, to some extent as breccia filling in the crusted parts of the sandstone, and as veins along joints, and bedding planes.The mine was first worked in 1917 and was operated during the war years. A long period of idleness was followed by intermittent operations in recent years. A small log-washing plant, consisting of a 20-foot log washer, was operated 1-1/4 miles northwest of the mine. The log-washer concentrates were crushed to minus- 1/2 inch and then washed in a second log washer to remove as much of the siliceous sandstone as possible. According to a communication from the operator, the double-washed concentrates were jigged and the jig concentrates marketed without further beneficiation."

Apr 1, 1942

By J. M. Pugliese

The Bureau of Mines, in support of its overall goal of helping to meet future U.S. demand for minerals, undertook this study to aid the quarry entrepreneur and/or operator in developing quarries near urban areas. In response to increased environmental concerns, the quarry operator often must take steps beyond those required in the last decade toward gaining permits for quarrying near metropolitan areas. Following the steps suggested in this report should increase the chances to obtain the permits to open and develop a quarry. Each task and question in the general plan flow diagrams are described in detail, with the flow diagrams aimed at the goal of acquiring the necessary permits. The appendixes include (1) types of projects for which Environmental Impact Statements (EIS's) may be prepared and Federal agencies responsible for preparing them, (2) State contacts for information regarding environmental impact assessment requirements and mining and mineral land reclamation laws, (3) a checklist of environmental inventory factors, (4) a tabulation of different regulations that affect mining in Michigan and the number of townships and counties that have each of the listed regulations, and (5) environmental logic associated with site selection. A central recommendation is that the quarry entrepreneur and/or operator coordinate plans at the beginning with local government officials (such as township supervisors and/or city and county planning board members), State and Federal officials, and public groups that will be affected.

Jan 1, 1979

By Kenneth M. Maas

The Bureau of Mines inventoried the land in southwestern Alaska to classify ownership and availability and compared this land with known mineral terranes and mineral deposits. This report discusses and quantifies the potential for favorable location of mining claims for metalliferous (locatable) mineral deposits. Of the nearly 24 million acres that constitute the study area, approximately 3.6 million acres or 17% are available for mineral location, 3.4 million acres or 14% are available with restrictions, and 17 million acres or 71% are unavailable. Mineral terranes are known to underlie about 7.8 million acres or 33% of the study area; 3 million acres or 38% occur on land available for mineral location, 1.3 million acres or 17% occur on land available with restrictions, and 3.5 million acres or 45% occur on unavailable land. The State of Alaska has opened over 91 % of its land in the study area to mineral location; in comparison, the Federal Government allows mineral location on 0.07% of the land under its jurisdiction. There are 117 known mineral deposits or occurrences within the study area, including 77 lode deposits and 40 placer deposits. Of the 41 lode deposits occurring within a mineral terrane, 2 occur on available land.

Jan 1, 1988

To improve the ventilation of large-opening under-ground stone mines by using stoppings made from stone left in place. Background Underground stone mines typically use large room-and-pillar openings with little ventilation control. Stone miners may be exposed to contaminants that include silica dust, diesel particulate matter (DPM), exhaust gases, nuisance dust, and face shot (blasting) fume gases. The health risks from breathing these fine particles and toxic organic materials are well documented. Although contaminants such as dust or diesel exhaust can be some-what controlled at the source, the escaping contaminants are often diluted and removed from work areas using ventilation with minimal controls. In many cases, current mine ventilation practices use trial-and-error techniques to improve ventilation. The growing realization of the importance of a healthy work environment along with increased regulations will require many stone mines to implement new ways to improve ventilation. In-place stone stoppings are one option. Mine air flows from one point to another because of a pressure differential between those points. This pressure differential is established using a mechanical fan in conjunction with separations (stoppings) between high-pressure (intake) and low-pressure (return) airways. The separation of intakes and returns is an important concept that is used in most other types of mines. Normally, air moves through underground stone mines with minimal control technology. Fans are placed in locations where they are thought to be most beneficial, and intakes are not separated from returns. In a few smaller underground stone mines, proper ventilation can be achieved with a few strategically placed fans. However, as these mines increase in size, moving adequate quantities of air through-out the mine becomes harder, and separation of intakes and returns becomes a problem. Building traditional mine stoppings to separate the intake and return airways in entries with a cross-section area often exceeding 800 ft2 is difficult. The stoppings must be able to withstand both the dynamic pressure from face shots and the static pressures created by the fans. Construction and maintenance difficulties, as well as high costs, are the main factors preventing these traditional mine stoppings from gaining wide acceptance by the stone mining industry.

Dec 1, 2002

This publication is the fourth in a series of miners? circulars covering various phases of accident prevention in bituminous-coal mines; these circulars constitute a text hook for courses of instruction on accident prevention in bituminous-coal minim. To these may be added material of particular interest in the field where the course is presented. Other circulars in the series are: Accident Statistics as an Aid to Prevention of Accidents in Bituminous-Coal Mines (Miners? Circular 47). Accidents from Falls of Roof and Coal in Bituminous-Coal Mines (Miners' Circular 48). Accidents from Hoisting and Haulage in Bituminous-Coal Mines (Miners' Circular 49).

Jan 1, 1946

By F. Keith Shelton

"INTRODUCTION Cobalt is an essential metal in the normal industrial ac¬tivity of the United States. Being an important constituent of high-speed steels and other cutting-tool materials, it becomes of critically essential importance during periods of national emergency. 3/ The Presidential order of December 20, 1940, included cobalt among other essential commodities that could be exported only under license. The Executive order 4/ listed cobalt metal, cobalt oxide, and alloys containing more than 5 per¬cent cobalt as being within the licensing requirements.There was no domestic marketed production of, cobalt products from 1931 until 1940 when the Pyrites Co. 5/ produced some cobalt oxide. The major portion of the domestic cobalt requirements has been obtained from Northern Rhodesia, the Belgian Congo, and French Morocco. 6/ The uncertainty of sea transportation from those sources of supply demanded that steps be taken to obtain from domestic raw materials an adequate supply of cobalt for use in the materials required for production of indispensable machined war metal products. In connection with the national policy for attaining self-sufficiency of strategic and critical materials, the Bureau of Mines, Boulder City, Nev., Experiment Station initiated studies to recover cobalt from the low-grade oxidized cobalt deposits in the Goodsprings district, Nevada. Hewett 7/ reported occurrence of cobalt specifically in the Blue Jay, Columbia, Copper Chief, and Highline mines and generally over a widespread area in the district."

Jan 1, 1946

By R. D. Groves

Laboratory research has demonstrated that high - grade copper powders can be produced under controlled conditions from cement copper products . The technique should enable small producers to prepare a directly marketable product by means other than smelting and electrolytic purification . A continuous drum- type precipitator was the preferred unit for producing fine - sized particles of cement copper that were further processed by chemical digestion in a copper sulfate solution , by reduction and sintering in a hydrogen atmosphere , and by grinding to a powder . The effects of variables related to all stages of the process were investigated . Treatment of leach solutions from three different sources resulted in copper powders containing 99.2 to 99.8 pct Cu , apparent densities of 1.97 to 2.25 grams per cu cm , good powder flow rates , and a size distribution of 54.9 to 60.1 pct minus 325 - mesh material .

Jan 1, 1964